Flint is a Equip Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Flint is Unlimited.
YGOPRODeck lists Flint for these formats: GOAT, OCG GOAT, Speed Duel, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Flint appears in Dark Revelation Volume 3 (DR3-EN102) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Flint is about $0.11 on Cardmarket (prices change frequently).
